Prediction of Lactate Threshold and Fixed Blood Lactate Concentrations from 3200-m Running Performance in Male Runners

Abstract

To determine the effectiveness of a 3200-m time trial for predicting V̇O₂ and running velocity at lactate threshold (LT), fixed blood lactate concentrations of 2.0, 2.5, and 4.0 mM, and peak, 42 male runners (X̄ age = 31.1 ± 8.3 years; X̄ ht = 176.8±6.6 cm; X̄ wt = 70.4 ± 10.0 kg) completed a V̇O₂ peak/LT test and a 3200-m time trial. The continuous treadmill protocol started at 0% grade 150 m/min and increased 10 m/min every 3 min until exhaustion. Velocity at LT, 2.0, 2.5, and 4.0 mM was determined from individual velocity blood lactate relationships, and V̇O₂ values were determined from individual plots ov V̇O₂ vs velocity. V̇O₂ peak and velocity peak were chosen as the highest values observed. Oxygen uptake at LT, 2.0, 2.5, 4.0 mM, and peak was 52.51, 56.61, 58.31, 61.70, and 64.21 ml/kg·min^-1, respectively, while the velocities associated with LT, 2.0, 2.5, 4.0 mM, and peak were 235.5, 251.5, 259.8, 273.5, and 285.5 m/min, respectively. During the 3200-m time trial (X̄ time = 11.28±0.96 min), 400-m split times and cumulative times were recorded. Twenty-nine subjects were randomly assigned to a validation sample and the remaining subjects were used for cross-validation purposes. Regression analysis revealed that a 3200-m time trial was a good predictor of both V̇O₂ (ml/kg·min^-1) and velocity (m/min) at LT, 2.0, 2.5, 4.0 mM, and peak. In the validation sample correlation coefficients between 3200-m time and velocity at LT, 2.0, 2.5, 4.0 mM, and peak were r=0.85, 0.85, 0.86, 0.88, and 0.87, respectively, and the standard error of estimate ranged from ±11.1 m/min (3.9% for velocity max) to ±14.5 m/min (6.2% for velocity LT). For V̇O₂ (ml/kg· min^-1) correlation coefficients ranged from r=0.73 (3200-m time vs V̇O₂ peak) to r=0.79 (3200-m time vs V̇O₂ 4.0 mM) with standard errors of estimate ranging from ±6.7% (V̇O₂ 4.0 mM) to ±8.3% (V̇O₂ LT). In the cross-validation sample correlation coefficients between actual and predicted velocities ranged from r=0.88 (velocity 2.0 mM) to r=0.97 (velocity peak) while correlation coefficients between actual and predicted V̇O₂ values ranged from r=0.61 (V̇O₂ LT) to r=0.81 (V̇O₂ 2.5 mM). Mean differences between actual and predicted values in the cross-validation group were not significantly different for any variable. It was concluded that in male runners performance on a 3200-m time trial accurately predicts V̇O₂ and velocity at LT, 2.0, 2.5, 4.0 mM, and peak. The present findings have applicability for exercise prescription and running performance in male runners.

Key words

V̇O₂ max - anaerobic threshold - onset of blood lactate accumulation